Threaded steel couplings have been used for many years to join, or connect a wide assortment of casing, pipe, tubing, hose, as well as solid rod. Such threaded connection, particularly, when used in subsurface applications such as those involving oil, gas, or geothermal wells, require high torque make-up and break-out tools, which are generally combersome and awkward to operate, often resulting in serious injuries and occasional fatal injuries to the operating personnel.
Furthermore, the excessive amount of time required to make such threaded connections or disconnetions is an important factor since this procedure must be repeated over and over again. perhaps, several hundred times for subsurface applications involving deep wells. For example when connecting drill pipe together on a large hydraulic rotary drilling rig the following fifteen separate steps are necessary:
1. Place back-up tong around female end of drill-pipe stub. PA0 2. Place make-up tong around female end of drill-pipe stub. PA0 3. Wrap spinning chain around female half-coupling. PA0 4. Insert, or stab, the male end of drill pipe into female end of drill pipe. PA0 5. Throw spinning chain loops around male end of drill pipe. PA0 6. Spin-up the new section of drill pipe to the drill-pipe stub. PA0 7. Raise the make-up tongs to the male half-coupling. PA0 8. Raise the back-up tongs to the female half-coupling. PA0 9. Push the back-up tong forward to the bite position. PA0 10. Push the make-up tong forward to the bite position. PA0 11. Complete the threaded connection with the make-up tong. PA0 12. Push the back-up tong forward. PA0 13. Unlatch and remove the back-up tong. PA0 14. Push the make-up tong forward. PA0 15. Unlatch and remove the make-up tong. PA0 1. Insert, or stab. male end of the pipe into the female half-coupling. PA0 2. Place make-up fork on appropriate position on male half-coupling. PA0 3. Drive male half-coupling into female half-coupling, using common hammer or light maul. PA0 4. Remove make-up fork from male half-coupling.
The foregoing fifteen steps require a crew of three men working together around the rotary table--one to operate the back-up tong and the spinning chain, one to operate the make-up tong, and one to assist with the tongs and stab the drill pipe. The time required to accomplish all fifteen steps, some of which are performed simultaneously, is approximately 30 seconds.
By contrast, the applicant's invention does not require any high-torque make-up or break-out tools, but instead requires simple hand tools consisting of a common hammer, a two-pronged make-up fork, and a shoehorn break-out system. For example, when connecting pipe together for subsurface applications in volving deep wells, just four steps are required:
The foregoing four simple steps can be performed easily by just one man in approximately five seconds, which, not only drives the two half-couplings tightly and securely together, but also compresses the gasket, and seals the coupling, as well.
This type of threaded connection is not plagued by joint swelling problems in high-tensile-load and high-temperature subsurface applications involving deep oil, gas, and geothermal wells, and when completely made up, results in an internally-flush central passage through the coupling resembling that of internally-flush drill pipe. The internally-flush central passage, made possible by the compressible gasket system reduces the probability of fluid flow irregularities at the couplings, which otherwise might damage the coupling system as a result of concentrated erosion or cavitation.
In subsurface applications involving oil, gas and geothermal wells, continuous copper conductors are sometimes incorporated into the wall of pipe for the transmission of electrical signals or electrical power. Since the applicant's coupling system is unthreaded, and, therefore, nonrotating, and since the male half-coupling is guided into the female half-coupling by means of pins affixed to the male half-coupling which slide through corresponding slots in the female half-coupling, electric conductors from one pipe section to another can be aligned with greater ease compared to a threaded and rotating coupling system. When completely joined together the guiding pins also lock the two half couplings together so as to prevent the rotation of one relative to the other--thus providing perfect alignment of the electrical conductors from one pipe section to another.